Great Astronomers by Robert Stawell Ball (best ereader for students .txt) 📖

1855:—

 

“If, then, it be painfully evident to both, that under such

circumstances there CANNOT (whatever we may both DESIRE) be NOW in

the nature of things, or of minds, the same degree of INTIMACY

between us as of old; since we could no longer TALK with the same

degree of unreserve on every subject which happened to present

itself, but MUST, from the simplest instincts of courtesy, be each

on his guard not to say what might be offensive, or, at least,

painful to the other; yet WE were ONCE so intimate, an retain

still, and, as I trust, shall always retain, so much of regard and

esteem and appreciation for each other, made tender by so

many associations of my early youth and your boyhood, which can

never be forgotten by either of us, that (as times go) TWO OR

THREE VERY RESPECTABLE FRIENDSHIPS might easily be carved out from

the fragments of our former and ever-to-be-remembered INTIMACY.

It would be no exaggeration to quote the words: ‘Heu! quanto minus

est cum reliquis versari, quam tui meminisse!’”

 

In 1858 a correspondence on the subject of Quaternions; commenced

between Professor Tait and Sir William Hamilton. It was

particularly gratifying to the discoverer that so competent a

mathematician as Professor Tait should have made himself

acquainted with the new calculus. It is, of course, well known

that Professor Tait subsequently brought out a most valuable

elementary treatise on Quaternions, to which those who are anxious

to become acquainted with the subject will often turn in

preference to the tremendous work of Hamilton.

 

In the year 1861 gratifying information came to hand of the

progress which the study of Quaternions was making abroad.

Especially did the subject attract the attention of that

accomplished mathematician, Moebius, who had already in his

“Barycentrische Calculus” been led to conceptions which bore

more affinity to Quaternions than could be found in the writings

of any other mathematician. Such notices of his work were

always pleasing to Hamilton, and they served, perhaps, as

incentives to that still closer and more engrossing labour by

which he became more and more absorbed. During the last few

years of his life he was observed to be even more of a

recluse than he had hitherto been. His powers of long and

continuous study seemed to grow with advancing years, and his

intervals of relaxation, such as they were, became more brief

and more infrequent.

 

It was not unusual for him to work for twelve hours at a stretch.

The dawn would frequently surprise him as he looked up to snuff

his candles after a night of fascinating labour at original

research. Regularity in habits was impossible to a student who

had prolonged fits of what he called his mathematical trances.

Hours for rest and hours for meals could only be snatched in the

occasional the lucid intervals between one attack of Quaternions

and the next. When hungry, he would go to see whether any thing

could be found on the sideboard; when thirsty, he would visit the

locker, and the one blemish in the man’s personal character is

that these latter visits were sometimes paid too often.

 

As an example of one of Hamilton’s rare diversions from the all-absorbing pursuit of Quaternions, we find that he was seized with

curiosity to calculate back to the date of the Hegira, which he

found on the 15th July, 622. He speaks of the satisfaction with

which he ascertained subsequently that Herschel had assigned

precisely the same date. Metaphysics remained also, as it had

ever been, a favourite subject of Hamilton’s readings and

meditations and of correspondence with his friends. He wrote a

very long letter to Dr. Ingleby on the subject of his

“Introduction to Metaphysics.” In it Hamilton alludes, as he has

done also in other places, to a peculiarity of his own vision. It

was habitual to him, by some defect in the correlation of his

eyes, to see always a distinct image with each; in fact, he speaks

of the remarkable effect which the use of a good stereoscope had

on his sensations of vision. It was then, for the first time,

that he realised how the two images which he had always seen

hitherto would, under normal circumstances, be blended into one.

He cites this fact as bearing on the phenomena of binocular

vision, and he draws from it the inference that the necessity of

binocular vision for the correct appreciation of distance is

unfounded. “I am quite sure,” he says, “that I SEE DISTANCE with

EACH EYE SEPARATELY.”

 

The commencement of 1865, the last year of his life saw Hamilton

as diligent as ever, and corresponding with Salmon and Cayley. On

April 26th he writes to a friend to say, that his health has not

been good for years past, and that so much work has injured his

constitution; and he adds, that it is not conducive to good

spirits to find that he is accumulating another heavy bill with

the printer for the publication of the “Elements.” This was,

indeed, up to the day of his death, a cause for serious anxiety.

It may, however, be mentioned that the whole cost, which amounted

to nearly 500 pounds, was, like that of the previous volume,

ultimately borne by the College. Contrary to anticipation, the

enterprise, even in a pecuniary sense, cannot have been a very

unprofitable one. The whole edition has long been out of print,

and as much as 5 pounds has since been paid for a single copy.

 

It was on the 9th of May, 1865, that Hamilton was in Dublin for

the last time. A few days later he had a violent attack of gout,

and on the 4th of June he became alarmingly ill, and on the next

day had an attack of epileptic convulsions. However, he slightly

rallied, so that before the end of the month he was again at work

at the “Elements.” A gratifying incident brightened some of the

last days of his life. The National Academy of Science in America

had then been just formed. A list of foreign Associates had to be

chosen from the whole world, and a discussion took place as to

what name should be placed first on the list. Hamilton was

informed by private communication that this great distinction was

awarded to him by a majority of two-thirds.

 

In August he was still at work on the table of contents of the

“Elements,” and one of his very latest efforts was his letter to

Mr. Gould, in America, communicating his acknowledgements of the

honour which had been just conferred upon him by the National

Academy. On the 2nd of September Mr. Graves went to the

observatory, in response to a summons, and the great

mathematician at once admitted to his friend that he felt the end

was approaching. He mentioned that he had found in the 145th

Psalm a wonderfully suitable expression of his thoughts and

feelings, and he wished to testify his faith and thankfulness as a

Christian by partaking of the Lord’s Supper. He died at half-past

two on the afternoon of the 2nd of September, 1865, aged sixty

years and one month. He was buried in Mount Jerome Cemetery on

the 7th of September.

 

Many were the letters and other more public manifestations of the

feelings awakened by Hamilton’s death. Sir John Herschel wrote to

the widow:—

 

“Permit me only to add that among the many scientific friends whom

time has deprived me of, there has been none whom I more deeply

lament, not only for his splendid talents, but for the excellence

of his disposition and the perfect simplicity of his manners—so

great, and yet devoid of pretensions.”

 

De Morgan, his old mathematical crony, as Hamilton affectionately

styled him, also wrote to Lady Hamilton:—

 

“I have called him one of my dearest friends, and most truly; for

I know not how much longer than twenty-five years we have been in

intimate correspondence, of most friendly agreement or

disagreement, of most cordial interest in each other. And yet we

did not know each other’s faces. I met him about 1830 at

Babbage’s breakfast table, and there for the only time in our

lives we conversed. I saw him, a long way off, at the dinner

given to Herschel (about 1838) on his return from the Cape and

there we were not near enough, nor on that crowded day could we

get near enough, to

exchange a word. And this is all I ever saw, and, so it has

pleased God, all I shall see in this world of a man whose friendly

communications were among my greatest social enjoyments, and

greatest intellectual treats.”

 

There is a very interesting memoir of Hamilton written by De

Morgan, in the “Gentleman’s Magazine” for 1866, in which he produces

an excellent sketch of his friend, illustrated by personal

reminiscences and anecdotes. He alludes, among other things, to

the picturesque confusion of the papers in his study. There was

some sort of order in the mass, discernible however, by Hamilton

alone, and any invasion of the domestics, with a view to tidying

up, would throw the mathematician as we are informed, into “a good

honest thundering passion.”

 

Hardly any two men, who were both powerful mathematicians, could

have been more dissimilar in every other respect than were

Hamilton and De Morgan. The highly poetical temperament of

Hamilton was remarkably contrasted with the practical realism of

De Morgan. Hamilton sends sonnets to his friend, who replies by

giving the poet advice about making his will. The metaphysical

subtleties, with which Hamilton often filled his sheets, did not

seem to have the same attraction for De Morgan that he found in

battles about the quantification of the Predicate. De Morgan was

exquisitely witty, and though his jokes were always appreciated by

his correspondent, yet Hamilton seldom ventured on anything of the

same kind in reply; indeed his rare attempts at humour only

produced results of the most ponderous description. But never

were two scientific correspondents more perfectly in sympathy with

each other. Hamilton’s work on Quaternions, his labours in

Dynamics, his literary tastes, his metaphysics, and his poetry,

were all heartily welcomed by his friend, whose letters in reply

invariably evince the kindliest interest in all Hamilton’s

concerns. In a similar way De Morgan’s letters to Hamilton always

met with a heartfelt response.

 

Alike for the memory of Hamilton, for the credit of his

University, and for the benefit of science, let us hope that a

collected edition of his works will ere long appear—a collection

which shall show those early achievements in splendid

optical theory, those achievements of his more mature powers which

made him the Lagrange of his country, and finally those creations

of the Quaternion Calculus by which new capabilities have been

bestowed on the human intellect.

 

LE VERRIER.

 

The name of Le Verrier is one that goes down to fame on account of

very different discoveries from those which have given renown to

several of the other astronomers whom we have mentioned. We are

sometimes apt to identify the idea of an astronomer with that of a

man who looks through a telescope at the stars; but the word

astronomer has really much wider significance. No man who ever

lived has been more entitled to be designated an astronomer than

Le Verrier, and yet it is certain that he never made a telescopic

discovery of any kind. Indeed, so far as his scientific

achievements have been concerned, he might never have looked

through a telescope at all.

 

For the full interpretation of the movements of the heavenly

bodies, mathematical knowledge of the most advanced character is

demanded. The mathematician at the outset calls upon the

astronomer who uses the instruments in the observatory, to

ascertain for him at various times the exact positions occupied

by